Oh, No Methotrexate! structure of MTX (PubChem; NCBI) Methotrexate has been used in cancer wards for over 50 years. And like other beyond-patent meds, it’s become less profitable to manufacture MTX compared to much costlier new agents. Related Post navigation Previous: Is Oral Sex to Blame for the Surge in Cancer of the Mouth and Throat?Next: Counterfeit Drugs, A New Concern for Patients